Hormones and the Endocrine System | Johns Hopkins Medicine Health Library Hormones and the Endocrine System See related health << Back to Diseases and Conditions The endocrine system uses hormones to control and coordinate your body's internal metabolism (or homeostasis) energy level, reproduction, growth and development, and response to injury, stress, and environmental factors. Consider the following hormones and their role in the workings of the endocrine system: Where the hormone is produced Hormone(s) secreted Regulates salt, water balance, and blood pressure Adrenal glands Corticosteroid Controls key functions in the body; acts as an anti-inflammatory; maintains blood sugar levels, blood pressure, and muscle strength; regulates salt and water balance Affects water retention in kidneys; controls blood pressure Pituitary gland Adrenocorticotropic hormone (ACTH) Controls production of sex hormones (estrogen in women and testosterone in men) and the production of eggs in women and sperm in men.

Pituitary gland Affects growth and development; stimulates protein production; affects fat distribution Pituitary gland Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) Controls production of sex hormones (estrogen in women and testosterone in men) and the production of eggs in women and sperm in men Pituitary gland Stimulates contraction of uterus and milk ducts in the breast Pituitary gland Initiates and maintains milk production in breasts; impacts sex hormone levels Pituitary gland Stimulates the production and secretion of thyroid hormones Kidneys Controls blood pressure, both directly and also by regulating aldosterone production from the adrenal glands Kidneys Affects red blood cell (RBC) production Pancreas e.hormone | Endocrine System : Hormone Glands Endocrine System Hormone Function: Develop & maintain female sex organs & characteristics; Initiates building of uterine lining Hormone Regulator: Follicle-stimulating hormone (FSH) Ovary (Corpus Luteum) Hormone Released: Progesterone & Estrogens Hormone Structure: Steroid Hormone Function: Influences breast development and menstrual cycles; Promotes growth and differentiation of uterine lining; Maintains pregnancy Hormone

 Regulator: FSH & Luteinizing hormone Hormone Released: Androgens (mainly testosterone) Hormone Structure: Steroid Hormone Function: Develop & maintain male sex organs & characteristics; aid sperm production Hormone Regulator: FSH & LH Hormone Function: Lowers blood sugar; Increases glycogen storage in liver; Stimulates protein synthesis Hormone Regulator: Blood glucose concentrations Hormone Released: Glucagon Hormone Function: Stimulates glycogen breakdown in liver; Increases blood sugar (glucose) concentration Hormone Regulator: Blood glucose & amino acid concentrations Hormone Released: Somatostatin Hormone Function: Suppresses release of insulin & glucagon Hormone Regulator: Nervous system, feedback from growth hormone Adrenal Glands (Medulla And Cortex) Hormone Released: Epinephrine (adrenaline) Hormone Structure: Amino Acid Derivative (Catecholamine) Hormone Function: Constricts blood vessels in skin, kidneys and gut which increases blood supply to heart, brain and skeletal muscles and leads to increased heart rate & blood pressure; Stimulates smooth muscle contraction; Raises blood glucose levels which increases available energy Hormone Regulator: Sympathetic nervous system Hormone

 Released: Norepinephrine (noradrenaline) Hormone Structure: Amino Acid Derivative (Catecholamine) Hormone Function: Constricts blood vessels throughout the body; Increases heart rate & contraction of cardiac muscles; Increases metabolic rate Hormone Regulator: Sympathetic nervous system Hormone Released: Glucocorticoids (mainly cortisol & corticosterone) Hormone Structure: Steroids Hormone Function: Regulates blood glucose concentrations by affecting many aspects of carbohydrate metabolism; Affects growth; Decreases effects of stress and anti-inflammatories Hormone Regulator: Corticotopin- releasing hormone (CRH) from hypthalamus; Adrenocorticotropic hormone (ACTH) Hormone Released: Mineralocorticoids (mainly aldosterone) Hormone Structure: Steroid Hormone Function: Regulates sodium, water & potassium excretion by the kidney Hormone Regulator: Renin & Angiotensin Hormone Released: Gonadocorticoids (mainly androgens (male sex hormones)) Hormone Structure: Steroid Hormone Function: Contribute to secondary sex characteristics (particularly after menopause in women) Hormone Regulator: Adrenocorticotropic hormone (

ACTH) Endocrine System: Discover the Anatomy and Function of Glands Oxytocin Antidiuretic hormone (ADH) All of the releasing and inhibiting hormones affect the function of the anterior pituitary gland.

TRH stimulates the anterior pituitary gland to release thyroid-stimulating hormone. GHRH and GHIH work to regulate the release of growth hormone—GHRH stimulates growth hormone release, GHIH inhibits its release. GnRH stimulates the release of follicle stimulating hormone and luteinizing hormone while CRH stimulates the release of adrenocorticotropic hormone. The last two hormones—oxytocin and antidiuretic hormone—are produced by the hypothalamus and transported to the posterior pituitary, where they are stored and later released. Pituitary Gland The pituitary gland , also known as the hypophysis, is a small pea-sized lump of tissue connected to the inferior portion of the hypothalamus of the brain. Many blood vessels surround the pituitary gland to carry the hormones it releases throughout the body. Situated in a small depression in the sphenoid bone called the sella turcica, the pituitary gland is actually made of 2 completely separate structures: the posterior and anterior pituitary glands. Posterior Pituitary: The posterior pituitary gland is actually not glandular tissue at all, but nervous tissue instead.

The posterior pituitary is a small extension of the hypothalamus through which the axons of some of the neurosecretory cells of the hypothalamus extend. These neurosecretory cells create 2 hormones in the hypothalamus that are stored and released by the posterior pituitary: Oxytocin triggers uterine contractions during childbirth and the release of milk during breastfeeding. Antidiuretic hormone (ADH) prevents water loss in the body by increasing the re-uptake of water in the kidneys and reducing blood flow to sweat glands. Anterior Pituitary: The anterior pituitary gland is the true glandular part of the pituitary gland. The function of the anterior pituitary gland is controlled by the releasing and inhibiting hormones of the hypothalamus. The anterior pituitary produces 6 important hormones: Thyroid stimulating hormone (TSH), as its name suggests, is a tropic hormone responsible for the stimulation of the thyroid gland. Adrenocorticotropic hormone (ACTH) stimulates the adrenal cortex, the outer part of the adrenal gland, to produce its hormones.

Follicle stimulating hormone (FSH) stimulates the follicle cells of the gonads to produce gametes—ova in females and sperm in males. Luteinizing hormone (LH) stimulates the gonads to produce the sex hormones—estrogens in females and testosterone in males. Human growth hormone (HGH) affects many target cells throughout the body by stimulating their growth, repair, and reproduction. Prolactin (PRL) has many effects on the body, chief of which is that it stimulates the mammary glands of the breast to produce milk. Pineal Gland The pineal gland is a small pinecone-shaped mass of glandular tissue found just posterior to the thalamus of the brain. The pineal gland produces the hormone melatonin that helps to regulate the human sleep-wake cycle known as the circadian rhythm. The activity of the pineal gland is inhibited by stimulation from the photoreceptors of the retina. This light sensitivity causes melatonin to be produced only in low light or darkness. Increased melatonin production causes humans to feel drowsy at nighttime when the pineal gland is active.

Thyroid Gland The thyroid gland is a butterfly-shaped gland located at the base of the neck and wrapped around the lateral sides of the trachea. The thyroid gland produces 3 major hormones: Calcitonin Triiodothyronine (T3) Thyroxine (T4) Calcitonin is released when calcium ion levels in the blood rise above a certain set point. Calcitonin functions to reduce the concentration of calcium ions in the blood by aiding the absorption of calcium into the matrix of bones. The hormones T3 and T4 work together to regulate the body’s metabolic rate. Increased levels of T3 and T4 lead to increased cellular activity and energy usage in the body. Parathyroid Glands The parathyroid glands are 4 small masses of glandular tissue found on the posterior side of the thyroid gland. The parathyroid glands produce the hormone parathyroid hormone (PTH), which is involved in calcium ion homeostasis. PTH is released from the parathyroid glands when calcium ion levels in the blood drop below a set point. PTH stimulates the osteoclasts to break down the calcium containing bone matrix to release free calcium ions into the bloodstream.

PTH also triggers the kidneys to return calcium ions filtered out of the blood back to the bloodstream so that it is conserved. Adrenal Glands The adrenal glands are a pair of roughly triangular glands found immediately superior to the kidneys. The adrenal glands are each made of 2 distinct layers, each with their own unique functions: the outer adrenal cortex and inner adrenal medulla. Adrenal cortex: The adrenal cortex produces many cortical hormones in 3 classes: glucocorticoids, mineralocorticoids, and androgens. Glucocorticoids have many diverse functions, including the breakdown of proteins and lipids to produce glucose. Glucocorticoids also function to reduce inflammation and immune response. Mineralocorticoids, as their name suggests, are a group of hormones that help to regulate the concentration of mineral ions in the body. Androgens, such as testosterone, are produced at low levels in the adrenal cortex to regulate the growth and activity of cells that are receptive to male hormones. In adult males, the amount of androgens produced by the testes is many times greater than the amount produced by the adrenal cortex, leading to the appearance of male secondary sex characteristics.

Adrenal medulla: The adrenal medulla produces the hormones epinephrine and norepinephrine under stimulation by the sympathetic division of the autonomic nervous system. Both of these hormones help to increase the flow of blood to the brain and muscles to improve the “fight-or-flight” response to stress. These hormones also work to increase heart rate, breathing rate, and blood pressure while decreasing the flow of blood to and function of organs that are not involved in responding to emergencies. Pancreas The pancreas is a large gland located in the abdominal cavity just inferior and posterior to the stomach . The pancreas is considered to be a heterocrine gland as it contains both endocrine and exocrine tissue. The endocrine cells of the pancreas make up just about 1% of the total mass of the pancreas and are found in small groups throughout the pancreas called islets of Langerhans. Within these islets are 2 types of cells—alpha and beta cells. The alpha cells produce the hormone glucagon, which is responsible for raising blood glucose levels. Glucagon triggers muscle and liver cells to break down the polysaccharide glycogen to release glucose into the bloodstream.

The beta cells produce the hormone insulin, which is responsible for lowering blood glucose levels after a meal. Insulin triggers the absorption of glucose from the blood into cells, where it is added to glycogen molecules for storage. Gonads The gonads—ovaries in females and testes in males—are responsible for producing the sex hormones of the body. These sex hormones determine the secondary sex characteristics of adult females and adult males. Testes: The testes are a pair of ellipsoid organs found in the scrotum of males that produce the androgen testosterone in males after the start of puberty. Testosterone has effects on many parts of the body, including the muscles, bones, sex organs, and hair follicles. This hormone causes growth and increases in strength of the bones and muscles, including the accelerated growth of long bones during adolescence. During puberty, testosterone controls the growth and development of the sex organs and body hair of males, including pubic, chest, and facial hair. In men who have inherited genes for baldness testosterone triggers the onset of androgenic alopecia, commonly known as male pattern baldness. Ovaries: The ovaries are a pair of almond-shaped glands located in the pelvic body cavity lateral and superior to the uterus in females.

The ovaries produce the female sex hormones progesterone and estrogens. Progesterone is most active in females during ovulation and pregnancy where it maintains appropriate conditions in the human body to support a developing fetus. Estrogens are a group of related hormones that function as the primary female sex hormones. The release of estrogen during puberty triggers the development of female secondary sex characteristics such as uterine development, breast development, and the growth of pubic hair. Estrogen also triggers the increased growth of bones during adolescence that lead to adult height and proportions. Thymus The thymus is a soft, triangular-shaped organ found in the chest posterior to the sternum. The thymus produces hormones called thymosins that help to train and develop T-lymphocytes during fetal development and childhood. The T-lymphocytes produced in the thymus go on to protect the body from pathogens throughout a person’s entire life. The thymus becomes inactive during puberty and is slowly replaced by adipose tissue throughout a person’s life. Other Hormone Producing Organs In addition to the glands of the endocrine system, many other non-glandular organs and tissues in the body produce hormones as well.

Heart: The cardiac muscle tissue of the heart is capable of producing the hormone atrial natriuretic peptide (ANP) in response to high blood pressure levels. ANP works to reduce blood pressure by triggering vasodilation to provide more space for the blood to travel through. ANP also reduces blood volume and pressure by causing water and salt to be excreted out of the blood by the kidneys. Kidneys: The kidneys produce the hormone erythropoietin (EPO) in response to low levels of oxygen in the blood. EPO released by the kidneys travels to the red bone marrow where it stimulates an increased production of red blood cells. The number of red blood cells increases the oxygen carrying capacity of the blood, eventually ending the production of EPO. Digestive System: The hormones cholecystokinin (CCK), secretin, and gastrin are all produced by the organs of the gastrointestinal tract. CCK, secretin, and gastrin all help to regulate the secretion of pancreatic juice, bile, and gastric juice in response to the presence of food in the stomach. CCK is also instrumental in the sensation of satiety or “fullness” after eating a meal.

Adipose: Adipose tissue produces the hormone leptin that is involved in the management of appetite and energy usage by the body. Leptin is produced at levels relative to the amount of adipose tissue in the body, allowing the brain to monitor the body’s energy storage condition. When the body contains a sufficient level of adipose for energy storage, the level of leptin in the blood tells the brain that the body is not starving and may work normally. If the level of adipose or leptin decreases below a certain threshold, the body enters starvation mode and attempts to conserve energy through increased hunger and food intake and decreased energy usage. Adipose tissue also produces very low levels of estrogens in both men and women. In obese people the large volume of adipose tissue may lead to abnormal estrogen levels. Placenta: In pregnant women, the placenta produces several hormones that help to maintain pregnancy. Progesterone is produced to relax the uterus, protect the fetus from the mother’s immune system , and prevent premature delivery of the fetus. Human chorionic gonadotropin (HCG) assists progesterone by signaling the ovaries to maintain the production of estrogen and progesterone throughout pregnancy.

Local Hormones: Prostaglandins and leukotrienes are produced by every tissue in the body (except for blood tissue) in response to damaging stimuli. These two hormones mainly affect the cells that are local to the source of damage, leaving the rest of the body free to function normally. Prostaglandins cause swelling, inflammation, increased pain sensitivity, and increased local body temperature to help block damaged regions of the body from infection or further damage. They act as the body’s natural bandages to keep pathogens out and swell around damaged joints like a natural cast to limit movement. Leukotrienes help the body heal after prostaglandins have taken effect by reducing inflammation while helping white blood cells to move into the region to clean up pathogens and damaged tissues. Physiology of the Endocrine System Endocrine System vs. Nervous System Function The endocrine system works alongside of the nervous system to form the control systems of the body. The nervous system provides a very fast and narrowly targeted system to turn on specific glands and muscles throughout the body. The endocrine system, on the other hand, is much slower acting, but has very widespread, long lasting, and powerful effects.

Hormones are distributed by glands through the bloodstream to the entire body, affecting any cell with a receptor for a particular hormone. Most hormones affect cells in several organs or throughout the entire body, leading to many diverse and powerful responses. Hormone Properties Once hormones have been produced by glands, they are distributed through the body via the bloodstream. As hormones travel through the body, they pass through cells or along the plasma membranes of cells until they encounter a receptor for that particular hormone. Hormones can only affect target cells that have the appropriate receptors. This property of hormones is known as specificity. Hormone specificity explains how each hormone can have specific effects in widespread parts of the body. Many hormones produced by the endocrine system are classified as tropic hormones. A tropic hormone is a hormone that is able to trigger the release of another hormone in another gland. Tropic hormones provide a pathway of control for hormone production as well as a way for glands to be controlled in distant regions of the body. Many of the hormones produced by the pituitary gland, such as TSH, ACTH, and FSH are tropic hormones. Hormonal Regulation The levels of hormones in the body can be regulated by several factors.

The nervous system can control hormone levels through the action of the hypothalamus and its releasing and inhibiting hormones. For example, TRH produced by the hypothalamus stimulates the anterior pituitary to produce TSH. Tropic hormones provide another level of control for the release of hormones. For example, TSH is a tropic hormone that stimulates the thyroid gland to produce T3 and T4. Nutrition can also control the levels of hormones in the body. For example, the thyroid hormones T3 and T4 require 3 or 4 iodine atoms, respectively, to be produced. In people lacking iodine in their diet, they will fail to produce sufficient levels of thyroid hormones to maintain a healthy metabolic rate. Finally, the number of receptors present in cells can be varied by cells in response to hormones. Cells that are exposed to high levels of hormones for extended periods of time can begin to reduce the number of receptors that they produce, leading to reduced hormonal control of the cell. Classes of Hormones Hormones are classified into 2 categories depending on their chemical make-up and solubility: water-soluble and lipid-soluble hormones.

Each of these classes of hormones has specific mechanisms for their function that dictate how they affect their target cells. Water-soluble hormones: Water-soluble hormones include the peptide and amino-acid hormones such as insulin, epinephrine, HGH, and oxytocin. As their name indicates, these hormones are soluble in water. Water-soluble hormones are unable to pass through the phospholipid bilayer of the plasma membrane and are therefore dependent upon receptor molecules on the surface of cells. When a water-soluble hormone binds to a receptor molecule on the surface of a cell, it triggers a reaction inside of the cell. This reaction may change a factor inside of the cell such as the permeability of the membrane or the activation of another molecule. A common reaction is to cause molecules of cyclic adenosine monophosphate (cAMP) to be synthesized from adenosine triphosphate (ATP) present in the cell. cAMP acts as a second messenger within the cell where it binds to a second receptor to change the function of the cell’s physiology.

Lipid-soluble hormones: Lipid-soluble hormones include the steroid hormones such as testosterone, estrogens, glucocorticoids, and mineralocorticoids. Because they are soluble in lipids, these hormones are able to pass directly through the phospholipid bilayer of the plasma membrane and bind directly to receptors inside the cell nucleus. Lipid-soluble hormones are able to directly control the function of a cell from these receptors, often triggering the transcription of particular genes in the DNA to produce "messenger RNAs (mRNAs)" that are used to make proteins that affect the cell’s growth and function. Prepared by Tim Taylor, Anatomy and Physiology Instructor An Overview of the Adrenal Glands - Beyond Fight or Flight An Overview of the Adrenal Glands Beyond Fight or Flight Written by Robert M. Sargis MD, PhD Adrenal Gland Essentials The adrenal glands are two glands that sit on top of your kidneys that are made up of two distinct parts. The adrenal cortex—the outer part of the gland—produces hormones that are vital to life, such as cortisol (which helps regulate metabolism and helps your body respond to stress) and aldosterone (which helps control blood pressure).

The adrenal medulla—the inner part of the gland—produces nonessential (that is, you don’t need them to live) hormones, such as adrenaline (which helps your body react to stress). When you think of the adrenal glands (also known as suprarenal glands), stress might come to mind. And rightly so—the adrenal glands are arguably best known for secreting the hormone adrenaline, which rapidly prepares your body to spring into action in a stressful situation. But the adrenal glands contribute to your health even at times when your body isn’t under extreme stress. In fact, they release hormones that are essential for you to live. Anatomy of the Adrenal Glands The adrenal glands are two, triangular-shaped organs that measure about 1.5 inches in height and 3 inches in length. They are located on top of each kidney. Their name directly relates to their location (ad—near or at; renes—kidneys). Each adrenal gland is comprised of two distinct structures—the outer part of the adrenal glands is called the adrenal cortex. The inner region is known as the adrenal medulla. Hormones of the Adrenal Glands The adrenal cortex and the adrenal medulla have very different functions.

One of the main distinctions between them is that the hormones released by the adrenal cortex are necessary for life; those secreted by the adrenal medulla are not. Adrenal Cortex Hormones The adrenal cortex produces two main groups of corticosteroid hormones—glucocorticoids and mineralcorticoids. The release of glucocorticoids is triggered by the hypothalamus and pituitary gland . Mineralcorticoids are mediated by signals triggered by the kidney. When the hypothalamus produces corticotrophin-releasing hormone (CRH), it stimulates the pituitary gland to release adrenal corticotrophic hormone (ACTH). These hormones, in turn, alert the adrenal glands to produce corticosteroid hormones. Glucocorticoids released by the adrenal cortex include: Hydrocortisone: Commonly known as cortisol, it regulates how the body converts fats, proteins, and carbohydrates to energy. It also helps regulate blood pressure and cardiovascular function. Corticosterone: This hormone works with hydrocortisone to regulate immune response and suppress inflammatory reactions. The principle mineralcorticoid is aldosterone, which maintains the right balance of salt and water while helping control blood pressure.

There is a third class of hormone released by the adrenal cortex, known as sex steroids or sex hormones. The adrenal cortex releases small amounts of male and female sex hormones. However, their impact is usually overshadowed by the greater amounts of hormones (such as estrogen and testosterone) released by the ovaries or testes . Adrenal Medulla Hormones Unlike the adrenal cortex, the adrenal medulla does not perform any vital functions. That is, you don’t need it to live. But that hardly means the adrenal medulla is useless. The hormones of the adrenal medulla are released after the sympathetic nervous system is stimulated, which occurs when you’re stressed. As such, the adrenal medulla helps you deal with physical and emotional stress. You can learn more by reading a SpineUniverse article about the sympathetic nervous system . You may be familiar with the fight-or-flight response—a process initiated by the sympathetic nervous system when your body encounters a threatening (stressful) situation. The hormones of the adrenal medulla contribute to this response. Hormones secreted by the adrenal medulla are: Epinephrine: Most people know epinephrine by its other name—adrenaline.

This hormone rapidly responds to stress by increasing your heart rate and rushing blood to the muscles and brain. It also spikes your blood sugar level by helping convert glycogen to glucose in the liver. (Glycogen is the liver’s storage form of glucose.) Norepinephrine: Also known as noradrenaline, this hormone works with epinephrine in responding to stress. However, it can cause vasoconstriction (the narrowing of blood vessels). This results in high blood pressure. Disorders and Diseases of the Adrenal Glands There are multiple reasons why the adrenal glands might not work as they should. The problem could be with the adrenal gland itself, or the root cause may be due to a defect in another gland. Below are the most common disorders and diseases of the adrenal glands: Addison’s disease: This rare disorder may affect anyone at any age. It develops when the adrenal cortex fails to produce enough cortisol and aldosterone. To learn more, read our article about Addison's Disease . Adrenal cancer: Adrenal cancer is an aggressive cancer, but it’s very rare. Malignant adrenal tumors are rarely confined to the adrenal glands—they tend to spread to other organs and cause adverse changes within the body because of the excess hormones they produce.

To learn more, read our article about adrenal cancer . Cushing’s syndrome: Cushing’s syndrome is an uncommon condition that is essentially the opposite of Addison’s disease. It is caused by overproduction of the hormone cortisol. There are a variety of causes of this disorder—a tumor in the adrenal gland or pituitary gland could be to blame. To learn more, read our article about Cushing's syndrome . Congenital adrenal hyperplasia: This genetic disorder is characterized by low levels of cortisol. It’s common for people with congenital adrenal hyperplasia to have additional hormone problems such as low levels of aldosterone (which maintains a balance of water and salt). The adrenal glands have a multi-functional role in the endocrine system. The two very different parts of these glands, the medulla and cortex, regulate and maintain many of your internal processes—from metabolism to the fight-or-flight response. What do the adrenal glands do? What do the adrenal glands do? This document is available in Spanish What do the adrenal glands do?

The medulla is located in the center of the gland and makes adrenalineAdrenaline - the hormone that helps control the "fight or flight" response and puts the body on "high alert" (also known as epinephrine) and noradrenaline. These hormones are also known as epinephrine and norepinephrine. These hormones control the "fight or flight response" i.e. put your body on "high alert." These hormones increase the heart rate, increase blood pressure, increase the amount of oxygen you breathe in, and temporarily improve the eyesight. Adrenaline also causes the liver to release extra glucoseGlucose - sugar used by the body as energy , or sugar, into the bloodstream to provide instant energy. Things that cause the adrenal medulla to release adrenaline and noradrenaline include anxiety, pain, upright posture, exercise, and cold. Once released, these hormones are broken down into normetanephrine and metanephrines, which are metabolites or waste products. The cortex is located on the outer layer of the adrenal gland and makes a number of different hormones that help control the heart, kidneys, GI tract, bones, genitalia, and immune system.

These hormones control carbohydrate metabolism, muscular integrity, hemodynamic changes, and sexual maturity. The cortex makes 3 main types of hormones: Cortisol  CortisolCortisol - a glucocorticoid that controls glucose production and suppresses the immune system is a glucocorticoid. Glucocorticoids are hormones that control glucose production in the liver and protein breakdown in muscle. These hormones also decrease the immune response by suppressing inflammation and other parts of the immune system. The most powerful glucocorticoid is cortisol, which the body needs to function normally as well as to protect the body during stress. Aldosterone  AldosteroneAldosterone - a mineralocorticoid that controls blood pressure is a mineralocorticoid. Mineralocorticoids are hormones that control blood pressure by controlling the amount of fluid that the body holds onto. Aldosterone is the most powerful mineralocorticoid and causes the kidneys to hold onto more sodium, which leads to increased total body fluid. The more fluid the body holds onto, the higher the blood pressure may become. Aldosterone also directly affects the heart and blood vessels. Androgens and estrogen  Androgens and estrogens are sex-hormones.

These hormones control the growth of the reproductive organs (testicles and ovaries), development of male or female characteristics, and some parts of behavior. Androgens control the male reproductive system while estrogens control the female reproductive system. Endocrine System Organs, Glands | Hormones and Metabolism Disorders of the Endocrine System Endocrine Glands Glands are a group of cells that produce and release hormones directly into our blood stream in a process called secretion. There are 2 types of glands. Exocrine glands have ducts or channels which secrete chemicals such as saliva or sweat. Endocrine glands do not have ducts; they secrete hormones directly into the blood stream. Organs of the Endocrine System Hypothalamus The hypothalamus is located in the brain and links the nervous and endocrine systems to each other. It secrets hormones that put the pituitary gland into action. Pineal Gland The pineal gland is a small, pine-cone shaped endocrine gland in the brain. It produces melatonin, a derivative of serotonin, a hormone that affects wake/sleep patterns and seasonal functions.

Pituitary gland The pituitary gland, or hypophysis, is an endocrine gland about the size of a pea. It weighs less than an ounce and is one of the most important organs in the body. It is located at the base of the brain and is closely connected to the hypothalamus. The pituitary gland secretes nine hormones that regulate homeostasis by stimulating other endocrine glands to produce and secrete their own hormones. The pituitary gland has two components: the anterior (front) pituitary (or adenohypophysis) and the posterior (back) pituitary (neurohypophysis). The anterior lobe makes up most of the gland and releases the majority of the hormones. The smaller posterior lobe stores hormones but does not make them. It links the endocrine system with the nervous system by way of the hypothalamus.The pituitary gland is known as the ‘master’ endocrine gland. The hypothalamus controls the production of hormones in both lobes. The pituitary gland produces many important hormones, some of which act on other glands to make them produce hormones.

The pituitary gland releases at least 9 hormones that have important effects on the body—these include the thyroid stimulating hormone (TSH), adrenocorticotrophic hormone stimulates the adrenal glands. Thyroid The butter-fly shaped thyroid gland is one of the largest endocrine glands. The thyroid gland is in the front of the neck, just below the thyroid cartilage or “Adam’s apple”. The isthmus bridges the two lobes of the thyroid and is located below the cricoid cartilage. The thyroid gland controls how quickly the body uses energy (metabolism), calcium levels in the blood, how the body makes proteins, and how sensitive the body is to other hormones. It produces thyroid hormones, the principal ones being triiodothyronine (T3), thyroxine which can sometimes be called tetraiodothyronine (T4) and calcitonin. These hormones regulate the heart rate, the rate of metabolism and affect the growth and rate of function of many other systems in the body. T3 and T4 are made from iodine and tyrosine. Calcitonin slows down the rate at which bone is broken down decreasing the amount of calcium dissolved in the blood.

Parathyroid Gland The parathyroid gland controls calcium levels in the blood. The parathyroid is a small of glands around by the thyroid gland. They produce the parathyroid hormone or PTH, which increases the rate at which broke bone is broken down. As a result, more calcium is released into the blood. Parathyroid hormone works in partnership with calcitonin from the thyroid gland. The 2 hormones have the opposite effect. Through negative feedback they keep the calcium level in the blood stable. Hormonal output from the thyroid is regulated by the thyroid-stimulating hormone (TSH) produced by the anterior pituitary, which itself is regulated by thyrotropin-releasing hormone (TRH) produced by the hypothalamus. The thyroid gets its name from the Greek word for “shield” because of its shape. The most common problems of the thyroid gland are overactive thyroid gland, called hyperthyroidism, and an underactive thyroid gland, called hypothyroidism. Thymus The thymus is a specialized organ of the immune system. The thymus “educates” T-lymphocytes (T cells), which are critical cells of the adaptive immune system.

Adrenal Glands The small, triangular adrenal glands (also known as suprarenal glands) sit atop the kidneys . Each is divided into two distinct anatomic and functional organs. The adrenal cortex (the outer region which secretes corticosteroid hormones that affect metabolism (that is how food is stored and used), chemicals in the blood, and characteristics such as body shape and hairiness. The smaller, inner region—the adrenal medulla (which is part of the sympathetic nervous system)—is the body’s first line of defense against physical and emotional stress. They are mainly responsible for releasing hormones in response to stress through the synthesis of corticosteroids such as cortisol and catecholamines such as epinephrine (adrenaline) and norepinephrine. They also produce androgens. The adrenal glands affect kidney function through the secretion of aldosterone, a hormone that helps regulate the osmolarity of blood plasma. The adrenal glands help us deal with dress and as well as maintain homeostasis. Disorders of the adrenal glands include congenital defects such as adrenal hyperplasia, tumors, autoimmune disorders, infection, and impaired blood supply.

The adrenal cortex When looked at under a microscope, the adrenal cortex is made up of 3 distinct zones. the outermost zone secretes the hormone aldosterone, which inhibits the amount of sodium excreted in the urine, maintaining blood pressure and blood volume. The inner and middle zones together secrete hormones hydrocortisone, also called cortisol, corticosterone, as well as small amounts of androgen hormones. The rate of release and amount of secretion is controlled by other hormones made in the hypothalamus and pituitary. The adrenal medulla the adrenal major love is closely related to nervous tissue and secretes the hormone epinephrine and norepinephrine in response to stimulation by sympathetic nerves. these nerves are most active at times of stress. the release of these hormones increases the heart rate and why the airways in the lungs in order to pump more blood to the large muscles of the skeleton. The airways in the lungs are increased so that more oxygen can be taken in. As more blood is sent to the active organs less blood is sent to the internal organs. Pancreas The pancreas is a gland organ in the digestive system and endocrine system.

It is both an endocrine gland—producing several important hormones, including insulin, glucagon, somatostatin, and pancreatic polypeptide—and a digestive organ—secreting pancreatic juice containing digestive enzymes that help with the absorption of nutrients and digestion in the small intestine. These enzymes help to break down the carbohydrates, proteins, and fats. Ovaries The ovary is an ovum-producing reproductive organ, often found in pairs in the female reproductive system. Ovaries in women are analogous to testes in males—they are both gonads and endocrine glands. Our ovaries produce estrogen, progesterone, relaxin and inhibin. Testes The testicle is the male gonad. Like the ovaries in women to which they are homologous, testes are components of both the reproductive system and the endocrine system. The primary functions of the testes are to produce inhibin, sperm (spermatogenesis) and androgens, primarily testosterone. Hormones Hormones are powerful chemical messengers that our endocrine system uses to control various processes in our body. Hormones can be fat-soluble or water-soluble.

Endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. In the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site. This chemical changes inside the target cells and adjusts the rate at which a specific action happens, such as a contraction of the muscle. Hormones can have one target or several targets. Hormones are released when they get feedback from triggers. Some hormones work on specific cells while other hormones work throughout the body. The level of hormones in the body are controlled by feedback. It is important that the amount of hormones in our body is kept at the right level. If hormone levels get too high or too low, they can make us sick. Although hormones come in contact with many cells in the body, they only react with target cells. A hormone can have more than one target cell, and can have different effects on different targets. Luteininzing Hormone This is a pituitary hormone that helps regulate the function of the reproductive organs. It stimulates ovulation to release the egg in the woman’s ovaries. In men it triggers the testes to produce male reproductive hormones.

Prolactin This is a pituitary hormone that stimulates the production of milk in the breast. It is one of several hormones that stimulate milk production or lactation. Breast-feeding stimulates the pituitary gland to make more prolactin so that milk is made for as long as the baby breastfeeds. Oxytocin Oxytocin is a pituitary hormone that stimulates muscle contractions in the uterus during childbirth. These contractions cause the release of more oxytocin. This is a positive feedback reaction that makes the cycle continue until the baby is born. Oxytocin also stimulates the breasts to release milk when the baby feeds. Glucagon The hormone glucagon increases the level of sugar in the blood. It plays a vital part in maintaining the correct blood sugar level. It is made by the pancreas, a gland that is part of the endocrine system and the digestive system. The pancreas releases glucagon when the blood sugar level starts to fall. Glucogon makes cells release glucose, and helps convert glycogen, the form of glucose stored in the liver, back to glucose. As a result the blood sugar level rises. Your blood has enough glucose to keep you alive for just 15 min.

However, as glucose is used up, more is released to take its place. Reproductive Hormones Reproductive hormones control the reproductive development of boys and girls. The development of primary and secondary characteristics and regulate all reproductive related processes such as sperm and egg production. Primary reproductive characteristics are the development of the major reproductive organs. There are 3 main types of reproductive hormones—androgens, estrogen, and progesterone. Female Reproductive Hormone Estrogen is the female hormone made mainly in the ovaries. It not only makes the girl reproductive organs develop, and controls her monthly menstrual cycle. Progesterone is the female hormone that prepares the girls uterus for pregnancy every month. Some contraceptive pills have estrogen in them to prevent the ovaries from releasing their egg cells. Male Reproductive Hormone The male reproductive system consists of the penis, scrotum, and the 2 testes. A male reproductive system creates sperm cells that combined with a female egg to create a new human life. The testes and scrotum hang outside the body where it is cooler because it improves sperm production. Sperm cells look like microscopic tadpoles. Sperm is made in the testes, which are inside the scrotum.

Sperm cells leave the testes through epididymis. The epididymis connects to the vas deferens. Glands called seminal vesicles lie along the vas deferens and add fluids and nutrients to the sperm. The male reproductive system also produces the reproductive hormones needed to make sperm and for a boy to develop at puberty. The male reproductive hormone testosterone also stimulates bone and muscle growth Epinephrine Epinephrine is a hormone that works with out nervous system to prepare our body to cope with danger or stress. If you’re suddenly scared, your heart pounds, your breathing becomes steep and rapid. These are just two of the effects of epinephrine, also called adrenaline. Epinephrine is a very fast acting hormone that prepares our body for emergency action—also called the fight or flight reflex. It speeds up our breathing and heart rate and diverts extra blood to the muscles. At the same time it slows down digestion and makes the liver release glucose into the bloodstream so more fuel is available for the muscles to contract. Insulin Insulin is a hormone that reduces the level of sugar in our blood. Insulin is a protein made by the pancreas.

It is released when the blood sugar level rises and reduces the sugar in 2 ways. First it makes insulin take up the glucose. 2nd in makes the liver store glucose by turning it into glycogen. Insulin and glucagon have opposite effects. Together they form a negative feedback system that keep sugar levels within set limits. In people with diabetes this control system does not work properly and they made may need daily injections of insulin to keep their blood glucose levels within safe limits. Growth Hormone The growth hormone is a pituitary hormone that controls the body’s growth by stimulating cell division. It also increases the blood glucose level. If your body has too little growth hormone, the body fails to grow normally. Too much growth hormone can cause the body to grow more than usual. Thyroid-stimulating Hormone The thyroid stimulating hormone makes the thyroid gland produce thyroid hormones. Adrenocorticotrophic Hormone This hormone stimulates the adrenal glands to produce other hormones. Antidiuretic Hormone This pituitary hormone increases the amount of water in the blood. A diuretic is a substance that stimulates the body to produce urine by taking water out of the blood stream.

The antidiuretic hormone or vasopressin, have the opposite effect. It increases the amount of water that the kidneys return to the blood and makes arterioles constrict. As a result, more fluid is squeezed into a smaller space and blood pressure rises. Follicle-stimulating Hormone This hormone and the Luteininzing Hormone are used in reproduction in both men and women. They also affect the production of reproductive hormones. Growth Hormone The growth hormone encourages growth in children and teenagers, makes our bones stronger, and helps build muscle. Growth is controlled by hormones produced by the pituitary gland. Oxytocin Hormone Oxytocin encourages childbirth and makes the breasts release milk when breast-feeding a baby. Prolactin Hormone Chronic stress puts your health at risk - Mayo Clinic Chronic stress puts your health at risk Chronic stress can wreak havoc on your mind and body. Take steps to control your stress. By Mayo Clinic Staff Your body is hard-wired to react to stress in ways meant to protect you against threats from predators and other aggressors. Such threats are rare today, but that doesn't mean that life is free of stress.

On the contrary, you undoubtedly face multiple demands each day, such as shouldering a huge workload, making ends meet and taking care of your family. Your body treats these so-called minor hassles as threats. As a result you may feel as if you're constantly under assault. But you can fight back. You don't have to let stress control your life. Understanding the natural stress response When you encounter a perceived threat — a large dog barks at you during your morning walk, for instance — your hypothalamus, a tiny region at the base of your brain, sets off an alarm system in your body. Through a combination of nerve and hormonal signals, this system prompts your adrenal glands, located atop your kidneys, to release a surge of hormones, including adrenaline and cortisol. Adrenaline increases your heart rate, elevates your blood pressure and boosts energy supplies. Cortisol, the primary stress hormone, increases sugars (glucose) in the bloodstream, enhances your brain's use of glucose and increases the availability of substances that repair tissues. Cortisol also curbs functions that would be nonessential or detrimental in a fight-or-flight situation. It alters immune system responses and suppresses the digestive system, the reproductive system and growth processes.

This complex natural alarm system also communicates with regions of your brain that control mood, motivation and fear. When the natural stress response goes haywire The body's stress-response system is usually self-limiting. Once a perceived threat has passed, hormone levels return to normal. As adrenaline and cortisol levels drop, your heart rate and blood pressure return to baseline levels, and other systems resume their regular activities. But when stressors are always present and you constantly feel under attack, that fight-or-flight reaction stays turned on. The long-term activation of the stress-response system — and the subsequent overexposure to cortisol and other stress hormones — can disrupt almost all your body's processes. This puts you at increased risk of numerous health problems, including: Anxiety Adrenal Glands About Watch and Favorite Watch Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made. Favorite Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students. Adrenal Glands Adrenal glands are composed of the adrenal cortex and medulla; both produce hormones that control essential body functions and responses.

Learning Objective Distinguish between the hormones produced by the adrenal cortex and adrenal medulla and the functions they regulate Key Points The two major hormones produced by the adrenal cortex are the mineralocorticoids , which regulate the salt and water balance, and the glucocorticoids , which can regulate blood glucose and the body's inflammatory response. There are three main glucocorticoids: cortisol, corticosterone, and cortisone. The adrenal medulla produces the hormones epinephrine and norepinephrine ; these hormones regulate heart rate, breathing rate, cardiac muscle contractions, blood pressure, and blood glucose levels. Terms Full Text Adrenal Glands Adrenal glands are a pair of ductless glands located above the kidneys . Through hormonal secretions , the adrenal glands regulate many essential functions in the body, including biochemical balances that influence athletic training and general stress response. The adrenal glands consist of an outer adrenal cortex and an inner adrenal medulla, which secrete different hormones. Adrenal glands are located on top of the kidneys. These glands are composed of the adrenal cortex and the adrenal medulla. Adrenal Cortex The adrenal cortex is made up of layers of epithelial cells and associated capillary networks.

These layers form three distinct regions: an outer zona glomerulosa that produces mineralocorticoids; a middle zona fasciculata that produces glucocorticoids; and an inner zona reticularis that produces androgens , which are sex hormones that promote masculinity. Androgens are produced in small amounts by the adrenal cortex in both males and females. They do not affect sexual characteristics and may supplement sex hormones released from the gonads . The hormones made by the adrenal cortex supply long-term responses to stress. The two major hormones produced are the mineralocorticoids and the glucocorticoids. The mineralocorticoids regulate the salt and water balance, leading to the increase of blood volume and blood pressure. The main mineralocorticoid is aldosterone , which regulates the concentration of sodium ions in urine, sweat, pancreas, and saliva. Aldosterone release from the adrenal cortex is stimulated by a decrease in blood concentrations of sodium ions, blood volume, or blood pressure, or by an increase in blood potassium levels. The glucocorticoids regulate increases in blood glucose and also reduce the body's inflammatory response. The three main glucocorticoid hormones are cortisol, corticosterone, and cortisone.

The glucocorticoids stimulate the synthesis of glucose and gluconeogenesis (converting a non-carbohydrate to glucose) by liver cells. They also promote the release of fatty acids from adipose tissue. These hormones increase blood glucose levels to maintain levels within a normal range between meals. Cortisol is one of the most active glucocorticoids. It usually reduces the effects of inflammation or swelling throughout the body. It also stimulates the production of glucose from fats and proteins , which is a process referred to as gluconeogenesis. Aldosterone is one example of a mineralcorticoid. It signals the tubules in the kidney nephrons to reabsorb sodium while secreting or eliminating potassium. If sodium levels are low in the blood, the kidney secretes more renin , an enzyme that stimulates the formation of angiotensin from a molecule made from the liver. Angiotensin stimulates aldosterone secretion. As a result, more sodium is reabsorbed as it enters the blood. Aldosterone, the major mineralcorticoid, stimulates the cells of the distal convoluted tubules of the kidneys to decrease re-absorption of potassium and increase re-absorption of sodium.

This in turn leads to an increased re-absorption of chloride and water. These hormones, together with such hormones as insulin and glucagon , are important regulators of the ionic environment of the internal fluid. Adrenal Medulla The adrenal medulla contains large, irregularly-shaped cells that are closely associated with blood vessels. These cells are innervated by pre-ganglionic autonomic nerve fibers from the central nervous system . The adrenal medulla contains two types of secretory cells: one that produces epinephrine (adrenaline) and another that produces norepinephrine (noradrenaline). Epinephrine is the primary adrenal medulla hormone, accounting for 75 to 80 percent of its secretions. Epinephrine and norepinephrine increase heart rate, breathing rate, cardiac muscle contractions, blood pressure, and blood glucose levels. They also accelerate the breakdown of glucose in skeletal muscles and stored fats in adipose tissue. The release of epinephrine and norepinephrine is stimulated by neural impulses from the sympathetic nervous system . Secretion of these hormones is stimulated by acetylcholine release from pre-ganglionic sympathetic fibers innervating the adrenal medulla.

These neural impulses originate from the hypothalamus in response to stress to prepare the body for the fight-or-flight response.

Question: Which gland produces a hormone that increases heart rate and blood pressure in times of stress?
Answer: ADRENAL GLAND